Pregnancy Education Companion: weeks 20-21

Pregnancy education companion. Weeks 20-21. Things to consider.

So, you are now around 20 to 21 weeks of your pregnancy!

From now until you give birth, we will regularly send you new information about pregnancy.

Part 1. This stage of your pregnancy


Routine pregnancy appointments will be booked for dates around the following weeks of your pregnancy:

  • Week 22
  • Week 28
  • Week 32
  • Week 34
  • Week 36
  • Week 38
  • Week 40

At each appointment a midwife or doctor will:

  • follow up and discuss any tests you may have had or are about to have
  • check that you are physically well (check your blood pressure etc.)
  • answer any of your questions (you may like to write questions down before your visit)
  • check how your baby is growing. As your baby grows, they will also check where your baby is positioned by feeling your abdomen, measuring the size of your abdomen, and listening to your baby’s heartbeat.

You will have been asked to complete a series of blood tests before your first appointment. These check for:

  • blood group and iron levels
  • immunity to Rubella (German measles)
  • exposure to Hepatitis (a disease of the liver)
  • sexually transmitted diseases such as Syphilis and HIV (this test is offered with pre- and post-test counselling)
  • Thalassaemia (an inherited disorder that affects the production of haemoglobin in your blood)
  • vitamin D deficiency and hepatitis C – these tests will be offered to women who are at risk.

We also ask about:

  • whether you have support from family and friends
  • any previous miscarriages or abortions
  • family violence (for more information visit the Pregnancy, Birth and Baby website)

As mentioned previously, your blood tests will provide your blood type. These tests will also tell us if you have Rh positive or Rh negative blood. Most women are Rh positive.

If you are Rh negative and your baby is Rh positive, it may cause health problems in a pregnancy. These can be treated by offering Rh-negative patients Anti-D injections at 28 and 34 weeks.

Test results

You can find your test results through Health Hub, or they will be given to you at an appointment and can be discussed at that time.  

You cannot call and ask for test results to be given over the phone.

If your midwife or doctor has any concerns about your results, they will contact you by letter or telephone.

Estimating your baby’s due date

Your midwife or doctor can work out your due date at your first hospital visit. In general, an unborn baby spends around 38 weeks in the womb, but the average length of pregnancy (or gestation) is counted as 40 weeks. Pregnancy is counted from the first day of your last period, not the date of conception, which generally occurs two weeks later. A baby is considered full-term if it is birthed between 37 and 42 weeks.

Your baby’s estimated birth date is calculated using the information below:

  • the date of your last normal menstrual period
  • the pattern of your menstrual cycles, including how many days they generally last, and how frequent they are
  • an understanding of the type of contraception being used prior to the pregnancy
  • an understanding of any assisted contraception used or natural rhythms.

We also use a pregnancy dating calendar or wheel, and an ultrasound to help calculate your baby's estimated birth date.


An ultrasound (scan) is done with a machine that uses sound waves to create a picture of your baby, your uterus, and your pelvis. You can have an ultrasound several times during pregnancy to check how your baby is developing.

An ultrasound is considered safe for both you and your baby because it does not use ionising radiation. It is different to an x-ray.

A morphology scan is considered a routine antenatal test, usually done around the 18th – 20th week of pregnancy. It is an ultrasound that checks your baby’s size, body organs and the position of the placenta.

Early pregnancy scans & screening: dads | Raising Children Network  

Anatomy of a pregnancy

Early pregnancy scans & screening: dads | Raising Children Network

Throughout your pregnancy you will be hearing a lot about different parts of your body. Some terms may be new to you. Expect to hear these terms often:

Uterus - commonly called the womb (pronounced woom). The uterus is a muscular organ, similar in shape to an upside-down pear.

Fundus - the upper edge of the uterus is called the fundus. As the baby grows, the uterus gets bigger and the fundus rises. During a clinic visit, your doctor or midwife will measure the distance between your symphysis pubis bone and the fundus.

Cervix - the neck or entrance to the womb is called the cervix. This is a long, thick canal that is usually closed. As you get closer to your expected date of birth and usually with contractions, your cervix becomes softer, shorter, and then starts to open.

During pregnancy, a large amount of mucous develops in the cervix. This mucous is very sticky and contains lots of antibodies. This helps to prevent any infection travelling into the uterus. Often called a “mucousy plug”, this will be passed vaginally as the cervix starts to open, sometimes before labour begins or often after labour has started. This is called a “show’.

Endometrium - The lining of the uterus is called the endometrium. After your baby and placenta have been birthed, the endometrium will also be expelled. This uterine lining and bleeding from the placenta site will produce vaginal blood loss for approximately 7-14 days, sometimes longer.

Placenta - Sometimes called the afterbirth, the placenta is responsible for the growth of your baby. It begins to form soon after conception and is well established after the 10th day. There is good circulation through the umbilical cord by the 10th week of pregnancy.

The placenta supplies your baby with nutrients and oxygen, removes waste products and acts as a barrier against some substances. Substances such as alcohol, nicotine and other drugs can travel through your blood and into the placenta, passing on to your baby.

The placenta also produces hormones to help maintain the pregnancy. The placenta is commonly called the afterbirth because it is expelled from the uterus after the baby is born.

The placenta’s position is determined by where the placental cells attach to the wall of the uterus. This is normally in the upper area, however, sometimes it attaches lower down, near or over the cervix - this is called placenta praevia. This may lead to complications and sometimes causes bleeding in pregnancy. As a result, it may be necessary to have a caesarean birth.

Mostly, though, when the placenta is low early in pregnancy it will grow upwards, away from the cervix as the uterus gets bigger.

Amniotic fluid - this is often called  baby waters or liquor. This fluid is contained in the bag that surrounds your baby during pregnancy. The amount of fluid varies throughout your pregnancy.
The fluid provides five amazing functions:

  1. It maintains a consistent temperature within the uterus for your baby.
  2. It provides protection from minor bumps etc.
  3. It flows in and out of your baby’s lungs. At around 36 weeks the placenta produces another hormone that helps your baby’s lungs to mature and accept oxygen when they are born.
  4. Your baby swallows the fluid. This helps to develop their taste buds. The swallowed fluid goes into baby’s stomach. From here, it may pass through the kidneys and contribute to fresh amniotic fluid. Or it may be stored in the small and large bowel and later passed as meconium, a sticky, thick, dark green poo, after birth. 
  5. In a healthy pregnancy, the fluid is constantly being replaced by the baby’s urine and the placenta.

Usually the bag breaks either shortly before labour begins or once labour has started. Occasionally, it may break several weeks before your due date.

Contact the hospital immediately if you think your water bag has broken. Ring (03) 8345 3635.

Part 2. Things to consider

Part 2.1. Childbirth education

If this is your first baby, we suggest you book into our Childbirth education programs as soon as possible. There are a range of options to choose from.

It’s best to book in now as classes fill quickly. The earlier you book, the more choice you will have.  If you book too late you may miss out.
When booking your class remember that it is best to attend a program that begins around 28-32 weeks into your pregnancy.

We offer our Childbirth Education information in several ways:

Option 1. Live streamed classes

Booking and payment are required 

  • Weeknight or weekend programs are available
  • You must book and pay through Eventbrite                                                           

These programs give you the opportunity to learn more about what to expect during labour, birth, and the beginning of breastfeeding and caring for your baby at home.

To book:

  • open Eventbrite, sign in or make a new account
  • select the date and time of your program, then book and pay.

Other information:

  • programs in languages other than English are held during office hours
  • programs for multiple births are held in the evenings
  • health Care Card holders may receive a concession
  • new programs become available on the first of every month -three months in advance. For example, on 1st July, programs for October open.  

If you cannot find a program to suit you, there is a waiting list available for every program in Eventbrite. You could also consider our online option or look for an independent educator. Accredited Childbirth and Parenting Educators can be found on the Childbirth and Parenting Educators of Australia website.

To cancel a booking:

Cancel and request a refund directly through Eventbrite 

Option 2. Our free online information

This option is free and available anytime:                       

Part 2.2. Looking after yourself

Healthy eating for you and your baby

During pregnancy it is important for both you and your baby that you eat well. Pregnant women need more nutrients, but not necessarily more calories. This means you need to focus on the quality and variety of foods you eat rather than increasing the amount you eat.

If you eat regular meals and include a variety of foods, you will get most of the nutrients you need. Sometimes, though, it’s hard to meet all your nutrition needs through diet alone so supplements may be necessary.

A vegetarian diet can be very healthy if care is taken to replace animal foods adequately. If you exclude all animal foods, you will need a vitamin B12 supplement while you are pregnant and breastfeeding. Vitamin B12 is an important vitamin for brain development in your baby.

Healthy weight gain in pregnancy

Weight gain varies between women and may depend on your pre-pregnant weight. Weight gain averages from 11.5 to 16 kilograms. If you were under-weight at the start of your pregnancy you might gain a little more than average. If you were overweight you may aim to gain less.

However, strict dieting is not recommended.

Talk with your health professional about food, diet, nutrition, supplements and weight during pregnancy. Dietitians have specialist knowledge about nutrition during pregnancy and can give you expert advice about any problems with your diet. You can ask to see a dietitian at any time during your pregnancy.

More information on Food and nutrition in pregnancy

Safe food hygiene

Contaminated food can cause toxoplasmosis and listeria. These infections are extremely rare, but they can harm your developing baby.

Toxoplasmosis is caused by a tiny parasite found in raw meat and in cat faeces. Anyone can be infected with the parasite, but it is most serious if you are pregnant as you may pass the infection on to your baby. We recommend you avoid contact with cats faeces, as toxoplasmosis increases the risk of birth defects if parasites cross the placenta.

To reduce the risk of toxoplasmosis:

  • wash your hands well after handling pets or gardening
  • wash salad vegetables thoroughly
  • cook meat thoroughly
  • avoid contact with cat faeces and wear gloves to dispose of cat litter.

More information is available by visiting the Better Health Channel website or the We are Family website.  

Listeria is a bacterium that can contaminate food and cause infection. Although uncommon, listeria infection is very dangerous for you and your baby as it can cause miscarriagestillbirth or premature birth.

Newborn babies infected with listeria from their mother can become seriously ill with meningitis, blood poisoning or other infections.

To prevent listeria infection:

  • wash your hands, cooking utensils and chopping boards thoroughly
  • wash raw vegetables and fruit thoroughly
  • avoid high-risk foods. These include soft cheeses (such as ricotta, camembert, brie, blue cheese and feta), cold cooked chicken, cold sliced meats, pâté, uncooked or smoked seafood, pre-prepared salads, and soft-serve ice-cream
  • refrigerate leftover food as soon as it has stopped producing steam. When you reheat food make sure it is piping hot, as heat kills listeria.

More information is available on the Food Standards Australia New Zealand website.


Tea, coffee, cola drinks and energy drinks all contain caffeine. There are mixed research results about the effects of large amounts of caffeine on a developing baby. However, moderate amounts appear safe. This means up to three cups of coffee or five cups of tea a day.

Guarana, a caffeine substance, is used in some energy drinks such as V, Mother and Red Bull. These drinks are not recommended during pregnancy.

Smoking (for you or someone you live with)

It is recommended that you stop smoking or significantly reduce your cigarette intake during pregnancy. Your baby will immediately feel the benefits. It is never too late in pregnancy to stop.

Smoking increases the risk of miscarriage, premature birth or having a low-birth-weight baby. The baby is also more at risk of infections and longer-term health problems. Smoking in pregnancy and after the birth increases the risk of SIDS (Sudden Infant Death Syndrome) commonly known as cot death. It is recommended that there be no smoking in your baby’s environment, including in or near the house or in the car.

As soon as you think you may be pregnant, ask for advice and support for you and/or your partner to stop smoking. You can get free information, advice and support from a trained Quitline counsellor, or talk to your midwife and doctor.

For more information go to: Quitline – Tel: 137 848

Medicines, drugs, and alcohol

Not all medicines are safe during pregnancy and breastfeeding. This can include medicines that are prescribed, natural medicine or supplements, or over-the-counter medicines from the pharmacy or supermarket.

Remember to tell your:

  • doctor, nurse or midwife about all the medicines you are taking. Include over-the-counter medicines from your pharmacy, supermarket or health food store
  • doctor that you are pregnant or breastfeeding before they prescribe medicines for any conditions
  • chemist (pharmacist) that you are pregnant or breastfeeding before you buy medicines.

For more information, call the Women’s Medicines Information Service on (03) 8345 3190 (9am-4pm Monday to Friday except public holidays) or email

Complementary and alternative medicines

The use of complementary medicines and alternative medicines (CAM) in pregnancy has increased. These include a wide range of treatments such as acupuncture, chiropractic care, naturopathy, herbal preparations, homeopathic remedies and nutritional supplements. 

Unfortunately, very few CAM are known to be safe during pregnancy, and some herbal remedies can be harmful to your baby. If you are considering using a complementary therapy, please talk to your health provider (such as your doctor, nurse, midwife or pharmacist) for more information. 

You can also call the Women’s Medicines Information Service on (03) 8345 3190 (9am-4pm Monday to Friday except public holidays).

More information about Medicines in pregnancy,  Medicines in breastfeeding and Herbal Medicines in pregnancy and breastfeeding.

Alcohol in pregnancy

We don’t know how much alcohol is safe in pregnancy or when you are breastfeeding. Excessive use of alcohol can make your baby very sick. The safest approach is to not drink alcohol.

Tell us about your drug and alcohol use

If you are pregnant and using alcohol or other drugs, early pregnancy care is important for your baby’s development.

Your midwife or doctor can support you to reduce and stop using in a way that is safe. The Women’s Alcohol and Drug Service gives confidential information, advice, pregnancy care and counselling to women with alcohol and drug issues.

More information on Drug and Alcohol use in Pregnancy

Advice and support for an unexpected pregnancy

Although it may not seem like a common occurrence, unplanned pregnancies are common.

Everyone’s situation is different when they learn of their pregnancy. It is normal to feel both scared and excited at this news. Having access to good support and information can assist with any decisions you may wish to make if your pregnancy was unexpected.

Several services are available to support and provide accurate information. These include:

The Women’s fact sheets

We have developed many fact sheets on a range of women’s health topics including pregnancy, labour, and birth.

These can be found in the fact sheet section of our website. Many fact sheets are available in languages other than English.

We hope you found this information helpful.

If you have any health concerns, please talk to one of your health care professionals including your midwife, General Practitioner (GP) or your hospital doctor, etc.

We’ll be back in touch next week with more to read and learn. Stay safe and well.

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